Do men look at the body that much when fucking ?? Do they care about fat

So basically my bf wants to do a foursome with one boy and another girl , but now I’m a bit insecure about my weight I noticed I have back rolls and love handles. I am not that good in bed either I like for the men to do everything and It will be awkward for me if this other girl is doing backflips and riding and all and I am not bothered to do that .