Derek was the certified brawn of the BAU, the best at tackling unsubs and kicking down doors. That type of muscle took work, hard work. That's why he constantly trained at the gym, mostly public ones with jacked out guys at every corner.

But when he started dating you, you were supportive and wanted to come with him. So, to protect you because he knew how ruthless 'gym bros' were, he switched to a home gym. And he had to admit, you were great motivation.

Not that you worked out with him, but you did stuff like getting him water, holding his legs while he was doing sit ups and giving him a kiss when he reached you.

Like right now, he was doing push ups and you were on his back, counting them. You weren't alot of extra weight, not to him, so he easily pushed his body up even as the sweat beaded on his forehead.

"Just keep counting, baby." He muttered as you laid on your side.