Hmmm,
It isn’t whether they have had partners or how many, it is the circumstances and treatment during the last relationship and breakup that matter. In my situation it would be a no.
I have someone else now, but even if I didn’t, no. I am friends with most of my exes, very friendly with some, we have shared an important bit of past together but ultimately things didn’t work out. However, my last great love treated me like garbage, something I didn’t deserve and cannot reconcile. The break up hurt, badly, we were engaged. For a while I would have done anything to have her back. Now, no, I have respect for myself. We still see each other at social events, but rarely speak, and I am good with that.