baby momma drama?

I've been with my man for a little over 4 months and things are really serious between us... And he already has a child from a prior relationship that has been over for a significant amount of time. As any woman I believe would and should I am trying to build a simple relationship with the kid whenever he is with us. I adore him he's a beautiful kid. So for the holidays we went and bought him some gifts and I got some things from me.. She does not approve of me being around him. So now she is saying he cannot pick him up or give the gifts if I'm involved.. I have never met or spoke to her or wrongly of her and I'm just confused of how to react being the victim of this negative energy. As long as it's been happening I've brushed it off and remained humble but it's so upsetting now at the holiday time that he cannot enjoy his son and I feel like the reason.. Although the all I wanna do is enjoy the moment too.. Help!