Over-eating

Wally3

Is it possible for a bf'ed baby to over eat?  My LO tends to spit up a lot especailly if I feed him on both sides instead of just one (he looked hungry yesterday).  He doesn't seem to have relflux issues and if he likes being flat on his back he spits up less then if he is moved around / sitting / over our shoulder.  My 1st was a premie and had relux/spit up and I had to hold him upright after eating and sleep him on a slant or he was really fussy LO isn't like that.  How do I stop him from overeating if that is what it is?I'm not going to offer 2nd boob, but he is teething and acting hungry but I don't think he really is.  He is gaining wieght normally and is just over 3 months.