thank uuuuu. hm here's a few

one: the last thing charles wants to do when he's pregnant is move around, especially when he's further along, so he usually spends a lot of time in bed. it/the bedroom basically a permanent nest while he's pregnant. erik of course runs and gets him anything he wants from elsewhere in the house, though charles usually keeps a minifridge full of snacks + water in the bedroom, has all the things he immediately uses (phone, laptop, fave books, etc) in arm's reach, and one of those bed desks. erik often has to squeeze himself into the bed to sleep bc it's full of charles' nesting accoutrements (many blankets, pillows, etc) + various activities (bed desk, etc) and on top of that charles takes up a lot of room himself w/ his belly 😭 but erik never complains

two: charles loooooves belly rubs + belly massages, it feels good and it soothes him to have erik's hands on him, and he loves the way erik looks at his belly with awe and pride and love

three: omega and alpha couples often have trends in the kinds of pregnancies the omega has, and while charles has had single pregnancies, he's also had twins + triplets

four: after a couple pregnancies charles is capable of lactating year round, but when he's actual pregnant he lactates a lot. it doesn't take much stimulation at all for him to start to dribble. this is great for erik because he's obsessed with drinking charles' breastmilk. this is also good because (lore thing from My Omegaverse Lore) an alpha consuming their omegas breastmilk triggers hormonal changes in their body that make them better equipped to breed + protect (building muscle....genital size....load size 👀)

five: while charles doesn't have a heat while pregnant, the hormones make him very horny, almost like he's always in low level heat. that distaste for moving still applies though, and theyre more limited in the ways they can fuck when he's pregnant, so most of it is leisurely lusty fucking in bed (all day, if he can keep erik there).

erik's happy to oblige him, so charles spends lots of time when he's pregnant laid on his side with eriks behind him, rubbing charles' belly and fat milky nipples, fucking into his cunt from behind. other positions they love is charles in erik's lap, rolling his hips and grinding down his cock, cooing as the head pushes against his womb. sometimes when he's extra lazy, or after charles' spinal injury, erik will do most of the work, holding charles by the waist and rolling his own hips up into him, so his cockhead kisses charles' cervix over and over.

or, charles just laying back, legs spread, while erik devours his fat, soaked cunt and suckles on his clitcock. charles can't see erik over his huge belly, but its fine because he can hear all the obscene wet noises and he can feel erik's hunger and the taste of slick on his tongue, erik's cock dribbling pre on the nesting blankets as he feverishly humps the mattress 💜💙