My husband keeps fingering me in his sleep

Context, my (26F) husband (29M) has always been a cuddly sleeper. He’s been known to spoon anyone he shares a bed with even on guys trips or when sharing a bed with his brother. It’s always been a funny quirk of his that we tease him over. We have been married for almost 3 years, and in that time I’ve noticed him rubbing my butt in his sleep and occasionally grabbing a boob. It’s never bothered me. He’s an incredibly deep sleeper, and it’s obvious he’s not awake when doing these things.

Recently, I’ve been waking up in the middle of the night to him trying to finger me in his sleep over my pajamas. If I move his arm away and adjust myself he’ll stop. It’s not aggressive, and when I talk to him the next day he has no memory of it or any hot and heavy dreams it could be tied to. He’s not an overly sexual man either, at least not while awake. We have sex 1-2 a week because that’s where our libidos are at. We openly talk about sex so I know that if he wanted more he wouldn’t be afraid to mention it as we’ve had check in conversations many times throughout our relationship.

I just don’t know what to make of this new habit. Has anyone else experienced something like this before?

ETA: because this is Reddit, people keep asking about his behavior with his brother/friends. They wake up when he tries to spoon them and move him off. It’s never gone past that. I assume it’s a comfortability/prolonged physical touch thing.