She's never lied to him. Not seriously anyway. He figured she'd told him plenty of white lies before he'd learned the truth about the Stargate program. But usually she didn't get much beyond "deep space radar telemetry" before changing the subject. She was excellent at distractions, but he was so in love that most of the time all she had to do was smile and he was gone.
He had never been jealous in any relationship. He lived his life in an open truthful way, and was attracted to women who did the same. Ironically, it wasn't until he knew the truth about what Sam did for a living that he suspected she might have more secrets.
The suspicion stared with her team, the three men she worked with on a regular basis. She told stories about Daniel's intelligence and penchant for trouble and funny anecdotes about Telc's encounters with earth's culture. So it took him a while to realize that she rarely ever mentioned the fourth member of the team, her commanding officer, Colonel Jack O'Neill. He thought they were just colleges. Pete's first impression of the man was that he was much older than the others and less personable. So he simply assumed from the fact that if Sam ever even mentioned him, she referred to him as Colonel O'Neill that her relationship with him was distant.
Soon Pete and Sam grew closer, and he didn't think it was possible to be happier. One day he pressed her slightly that he'd like to get to know her friends and she responded by inviting her teammates over for dinner the next night. Although he offered to help her cook, she insisted on keeping it casual and ordering pizza.
Pete decided that the first clue that something was wrong should have been the nervous way she fluttered around her house that evening before their guests arrived. She moved with a kind of nervous energy that was foreign to her. However, instead of worrying, he decided that it indicated that she was as serious about their relationship as he was. Obviously she wanted to make a good impression on her teammates
Suddenly the doorbell rang and Sam fluttered over and opened it. Pete was left on the couch wondering exactly when Sam had started fluttering. All three men stood on the step. Sam invited them in and embraced Daniel warmly and took Teal'c's coat. Then Sam started babbling in nervously in the silence that followed. The colonel simply silenced her by holding up the case of beer he was carrying and heading for the kitchen. Later Pete figured the fact that he not only knew where the kitchen was but felt comfortable simply putting things in the fridge should have been the first sign his assumptions about Sam's relationship with this man were faulty.
So much later after the guests had left, as quickly as it was polite to leave, Pete broke into her nervous energy. But he asked the wrong question. Sam was just as tense and was now putting things away at an extremely rapid pace. He touched her shoulder gently and she paused. And instead of skirting the issue he asked the question he'd been wondering all night.
"Sam, are you sleeping with the colonel?" he asked gently. He felt tense, afraid to ask the question and even more apprehensive about the answer. She appeared surprised for a moment but then relief appeared on her face. She assured him contently that she'd never slept with the colonel and he was momentarily appeased. And her tension seemed to immediately disappear. She continued her cleaning, but at a much less frantic pace, even stopping occasionally to drop a small kiss on his lips. Yet, he had a odd nagging feeling that he still couldn't shake.
Later that night he lay awake in her bed, after making love with a passion that hadn't been present since the early stage of their relationship, he realized he'd asked the wrong question. She wasn't sleeping with her commanding officer; she was in love with him. And if the looks the colonel had give her at dinner were any indication the feeling was reciprocated.
She had never lied to him about the Colonel. He simply had never asked the right questions. Now he knew that he didn't intend to. He loved her. And she loved him, didn't she? Was he ok with the fact the she was in love with someone else? He had no idea, but even considering any scenario that ended with loosing her was almost unbearable
So he started thinking about the next question. The big one that involved a diamond and a new life with the beautiful blonde currently snoring softly next to him. He could only hope that it wasn't the wrong question.