If Tommy was physically capable of tearing his hair out in frustration, he was certain that he would be doing that right now.
Seriously. He loved Laurel and Thea, he really did, but if they'd just waited ten minutes, they wouldn't have interrupted Oliver trying to propose to Felicity. And now that they had interrupted him, who knew how long it would take for Oliver to try again?
When he'd first died- first came here, wherever here was- despite the fact that his every thought seemed to be catered to, it had been so utterly lonely. There had been countless clubs and bars and women, but not only was it not real, none of the people he loved- Laurel, Oliver, and Thea- had been there. He'd occasionally gone exploring, but the only familiar face he'd seen had been that of Robert Queen, and whenever Tommy had seen him, he'd looked so distracted and sad that Tommy had just decided to avoid him.
It had taken a bit of help, but he'd eventually discovered that he could actually look in on the lives of the people he loved and see how they were doing. Just in time, too- right around when he discovered how to do this, Oliver decided to return from the Island to Starling City (for the second time in as many years).
He hadn't been too surprised to see John Diggle becoming close to Oliver- he'd seen them together when he was alive, and he knew that in his own absence, Oliver would be seeking out someone to be his brother. What he had been surprised by was the presence of the terrifyingly smart, blond-haired spitfire that was Felicity Smoak.
When he was alive, he'd barely seen any glimpses of her- a flash of blond hair, an impression of vivid pink lipstick- hovering around Oliver. He honestly didn't even know her name. But when he watched them when Oliver came back again, it was abundantly clear that Felicity had been a part of Oliver's secret life, and an important one too, given how both Oliver and Diggle treated her. Oliver may have made her his EA, but it was obvious to anyone, especially someone who spent as much time watching them as Tommy did, that Felicity was Oliver's partner and equal.
He'd seen how Felicity looked at Oliver, and his first thought had been that Oliver was just using her, entangling her in his dangerous and recently much less suicidal mission by virtue of his charm and good looks, but that thought had only lasted for about, oh, a nanosecond. Felicity may have looked at Oliver with adoration and respect and friendship and a whole boatload of other emotions, but the way she demanded Oliver and Diggle's respect and admiration reminded him, oddly enough, of Oliver's mother.
When he could tear himself away from watching Laurel destroy herself out of grief for him- and god, Tommy wished he could have been alive, if only so that Laurel would be spared the pain she was going through- he watched Oliver, Felicity, and Diggle (and, later on, the Harper kid and surprisingly, Sara Lance) try to save the city. It was fascinating, really- especially when the first time that Oliver broke his no-killing rule (to honor Tommy's memory, how sweet) was to put three arrows in the chest of some criminal who was threatening Felicity.
(And, on a side note? "He had you and he was going to hurt you. There was no choice to make." Wow, Oliver, that totally didn't make it sound like you were utterly, desperately in love with Felicity Smoak.)
At that point, Tommy was a goner. He could honestly say that his time watching his loved ones was split evenly between Laurel, and Oliver and Felicity (and Diggle, who was great and why couldn't Tommy have still been alive, Diggle was awesome). If he'd needed to preserve his dignity in any way, he would have said that he didn't know why he spent a lot of time watching Oliver and Felicity, but he was dead, he didn't know anyone here, so there was really no shame in admitting that not only did he want Oliver to be happy, but he just liked the idea of Oliver and Felicity being together.
It had come as a horrible shock to watch Moira die on Slade Wilson's sword, and when Moira had first appeared up here, he had actually waited a bit before going to her. He was slightly happy that there was at least one familiar and slightly welcome face up here now, but he knew that the grief that everyone down there was experiencing had to be enormous.
Fortunately, it didn't take long for Moira to get used to being here, and to be honest, it was nice to have someone to reminisce about their lives, as well as keep an eye on their loved ones. He'd decided to show Moira early on how to watch over her family, to hold hands when one of them suffered a near-death experience- in short, to bond.
The summer after Moira died, both she and Tommy spent more and more time watching Oliver and Felicity grow closer and closer between "study dates" that only lacked date-appropriate physical activities to make them actual dates, daring rescues and taking down criminals, and even though Tommy hadn't liked Oliver's crusade when he first found out about it, he had to admit that the way things were going, it was a pretty worthy crusade.
When Oliver finally (finally!) asked Felicity out on a date, Moira had smiled. Tommy had let out an unrestrained whoop of excitement, not even caring that some people turned to stare at him. Oh, come on- Oliver was still his best friend, and it was adorable to watch him blush and stammer his way through asking Felicity out. Tommy couldn't even remember if Oliver had ever acted like this when he was alive.
Of course, when that asshole criminal decided to literally blow up their date, Tommy had been angry and disappointed that Oliver withdrew into his brooding Arrow armor fast enough to give Tommy whiplash. And seriously, it was actually really frustrating, watching Oliver be completely head-over-heels in love with Felicity, but being unwilling to do something like, oh, act on those feelings. Over the course of the next few months, there had been so many times that Tommy wished he was alive, if only so he could slap some sense into Oliver.
Then Team Arrow- as Tommy had taken to calling it- stopped Ra's Al Ghul from razing Starling City, and Tommy had been ecstatic over Oliver and Felicity literally driving off into the sunset (but not before Oliver had gone and picked up his mother's engagement ring in secret, which, wow, if Tommy wasn't dead already, he probably would have died of excitement). He'd watched as they traveled the world, Oliver becoming lighter and happier every day, and Tommy had actually thanked God that Oliver had met Felicity Smoak, because she was everything he could want for his best friend.
He'd been watching Oliver and Felicity with Moira when Oliver told the neighbors that he was going to propose to Felicity tonight, and he'd honestly been smiling so widely the whole day that his face would probably have hurt if he'd been alive.
Which was why he would be tearing his hair out in frustration now, because Oliver was just about to propose when Laurel and Thea knocked on the door, and now that wonderful, beautiful ring was not sitting on Felicity's finger like it should be, but was rather still hiding behind the frosting on the souffle. Seriously- Laurel and Thea had the absolute worst sense of timing. It was exactly the kind of dramatic twist he would have expected to see on a tv show.
As they got into the car, Tommy thought at least they're going back home again.