GotToBeInItToWinIt I would have thought skin to skin would lessen the risk of overheating - thought it helped baby to regulate temp?
OP, it's research statistics to do with placing baby to sleep on tummy. Current advice is on back, feet to foot of cot, no co-sleeping is the safest way to be, but this has changed over time (when I was a baby it was on tummy, my brother was on his side!). However I had a community midwife who was all for co-sleeping - then a HV that was horrified at the slightest chance of dozing with baby.
DD also BF, exclusively slept on her front on people's chests for the first few days, gradually night times moved to Moses basket for night but nap times always on chests, unless in pram/car. she has literally in the last couple of months (now 11 months) started having morning nap in the cot, but if she sleeps in the afternoon its on a chest. I used to fall asleep with her there too - exhaustion does that to you, don't feel bad.
If it is going to happen anyway, like you said you can't stop yourself, maybe try to make it as safe a possible - have you got a widgey pillow or something so he can't roll off? Or (if you wanted to consider co-sleeping - I never felt able to do this but a friend of mine did) try BFing on your side with baby next to you on the bed? that way he wouldn't roll off you.
She mostly slept on tummy in the cot as soon as she could roll over, incidentally...couldn't really stop her doing that in the night, even when she could only go one way.