What event officializes a 1 on 1 relationship?

I read this and proceeded from this point to ‘address the argument.’ I have no personal agenda here, I merely have an opinion which ‘majority rule’ appears to consider off topic. No problem. - Jess.

I did. Your interpretation of her comments is, i believe, incorrect.

Your disingenuousness is showing.

She’s not the only one.

Ok, to get on track with the OP, I’ll reiterate what I said and expound:

I wouldn’t have sex with someone unless I was in an exclusive relationship.

I wouldn’t be in an exclusive relationship unless we had had an actual conversation where we BOTH agreed that we were in an exclusive relationship.

Also back to the OP…

Officially together when we had a talk and agreed that we were officially monogamously together. Too much iffiness to risk otherwise, having uinintentionally burned and been burned by assuming a serious, monogamous relationship based on outward signs. Plain speaking is always prefereable to assumptions.