Someone once asked...

What would you do if you found out someone that you hooked up with has a partner which they lied about or hid from you but the make out was good and you needed it anyway?

Someone answered with kindness...

Bruh

Another soul answered...

I wouldn't do anything and just move on

Another soul answered...

Definitely do not continue and become party to an affair. Perhaps let the partner know. Don't beat yourself up for choices you made with incomplete information.