Spencer, as he liked to inform Derek, had grown up in a desert, he knew the evils of sand and it didn't matter if a large body of water was neighbouring it Spencer was not going to spend his spare time anywhere near sand.
Derek had humoured him, the beach wasn't for everyone besides they had plenty of fun on vacation else where, such aa Japan during their honeymoon. But Spencer couldn't say no when Sarah announced she was getting married on the beach. Spencer loved the happy family that was the Morgans and he was more than willing to put up with a beach for them.
They arrived a couple days before the ceremony and had hotel sex, they then went sight-seeing but staying well clear of the beach. Derek had suggested a picnic on the beach but the reply was a simple "do you know why they call it a sandwich? Because you always get sand in it." So that never happened.
They decided to spend the next day apart. They were in love and happily married, part of the their success was that they weren't joint at the hip. Derek went sunbathing while Spencer went antiquing. They both had a pleasant day. But at the sight of a sky on fire sunset Derek knew he wanted to share this with Spencer. It only took a text to summon the man to him.
Spencer sat himself next to Derek and wrapped the towel he had been sitting on around himself "the sun is setting Spencer it is hardly going to burn you now." All he received was a glare in return. That sat together admiring, Derek wrapped his arm around Spencer and handed him the sun cream bottle. He chuckled at the look on Spencer's face, he had found this particular brand on Spencer's favourite sex toy shop's website, usually they went into the physical store but Derek had been so excited that when he saw the sun cream that doubles as lube, he had clicked the 'buy now' button. Luckily he wasn't worried about Garcia looking at his internet history, she respected him and his privacy (the whole team's) to do something like that without express permission.
Derek had not brought condoms with him, they had stop using them after they had been together a couple of years and both been tested and found clean, the also regularly got themselves checked out to be on the safe side.
Derek grinned and leaned in for a kiss, but was halted by Spencer hand, "Derek, I've had sex on sand before, I am topping here," Derek shrugged in agreement, he didn't mind either way, "but trust me on this Derek, you don't want to do this, sand, lube, and sensitive body parts never mix well." Again Derek just shrugged, they were finally having beach sex, all they needed now was phone booth sex, while one of them was on the phone not trying to let the person on the other side of the line know, and then they'd have ticked off everywhere on 'Derek's Places To Have Sex With Spencer Volume One' list.
Derek lay himself down and Spencer got up on top of him, they started kissing, Derek tried to remove Spencer's clothing but he just scoffed and said "trust me on this", so they stayed on, their hands roamed over the clothes, and the feeling of being of close yet not there was intensified by the fact they were in public, granted the beach was empty but still the thrill of public sex was there. Derek moaned as Spencer paid attention to his erroneousness zones, the feeling of fabric adding a different dimension. Spencer tried to be quick, muttering about sand and the quicker they are the less exposure, but Derek slowed him down. Unfortunately, for Derek, Spencer knew exactly what he was doing and with a twist of his fingers he had Derek both fully prepared and begging.
Spencer pounded into Derek hard and fast, and they both loved it, moaning, their hands never leaving the other's body. They came spectacularly and loudly, and fell down together in a heep and began to snuggle. As much as Derek enjoyed cuddling doing so on the beach with sand in uncomfortable places wasn't something he wanted to do for long. But he stayed there with Spencer cradling each other, he couldn't let Spencer know he was right, the man would be insufferable. Eventually Spencer spoke, "do you think we should let Sarah know that there'll be rain tonight, and her under the stars beach wedding will be ruined?"