All My Buddies are Using my Stepmom's Mouth to Cum in

My dick is too small. That's what my stepmom said when I asked her if I could have a blowjob, too. I mean, all my friends come over day after day. They push their cocks in her mouth, or lay back and let her moan and drool over them. They plaster her face and tits with loads. In casual conversation, they'll remark about how her throat feels and tell me I'm missing out. But all I get to do is watch, humiliated, as everyone gets to use her mouth but me.