baby daddy

im not proud but was with 2 guys within a short time period and they r both possibly my baby daddy... the 1 stepped up said im not going anywhere, if u need anything ask (we are friends) the other was a 1 night stand, when i told him his response is im sterile... i asked for proof and have been ignored (convo thourgh fb), i think its an excuse to get out of respinsibility? what are your thoughts??? i hope eiyher way its not "sterile" guy