Does the butt become more malleable the more you do it?

I sorry if im using the wrong word and If this comes of as crude.But to start off I met my first legit guy.Older and surprisingly bigger then his pic.I was able to take it but there was some very slight discomfort and it didn't help that I was nervous.No real significant pain.So im just wondering when I meet him again will it be more comfortable?I do kegel exercises so I don't know if that means anything.Again im sorry if this was too much or crude.