How to Deal With the Other Biological Parent
A few possible scenarios exist: Out of sight out of mind — he is fine with your new relationship and is inclusive of both of you. Or he hates you and lets it be known.
The Other Biological Parent Doesn't Mind
In the first scenario, follow the lead of the other parent. If he is not concerned with you and is cordial when you bump into one another and that is that, great. There may not be a need for you two to communicate or interact. Maybe he deals solely with your girlfriend and is not bothered by you and does not want to bother with you. This is fine, and there is little need to force a friendship. If everyone is friendly and attends functions for the children together, he may be interested in being friends or at least somewhat more involved with you than you might have imagined. In this case, you can follow his lead. Forming a positive relationship will not only make you more comfortable when you interact with him, but will also make situations more pleasant for the children. These relationships are the easiest and don't take much explaining; the worst-case scenario, however, can be damaging to everyone.
Doing small things, like baking cookies and sending them over for her birthday or framing a picture of your stepchild for her, can be nice gestures to break the ice and should not be construed as over the top. If she throws them at you or tells you she does not appreciate the gestures, respect her wishes and gracefully stop. Do not bad mouth her or judge her for being disinterested in forming a relationship.
The Other Biological Parent Does Mind
If the breakup was difficult and the ex hates you and blames you for everything, you definitely should not follow his lead. He may be rude at family events, glare at you, bad mouth you to his children, or even threaten you. In any of these situations, do not buy into the behavior or support it; it will only make things worse. If he bumps into you every now and then and lets his presence be known, ignore him and gracefully stay out of his way. If he bad mouths you to the children and they tell you, do not dignify his words with a response; instead tell them you hope they form their own opinions of you as you spend more time together. If he threatens you or harms you in any way, have respect for yourself and the children and do not become physical with him. Instead, discuss with your significant other that it is clearly not the time for you to be around the ex, and come up with an arrangement where your paths do not need to cross.
