There's still no reason you wouldn't be able to do that. We still need rings. Of course, it would be more of a formality, but...most such things relating to romantic relationships are just formalities.

[Egon stares down at Venkman's hand intertwined in his. A surge of unidentified emotion in his chest makes it suddenly difficult to breathe. He's fairly certain, however, that the emotion is positive.]

What? No. You were the one who chose to speak about your desire to marry.