People have different emotions surfacing ....

I once dated a girl that giggled every time she orgasmed ....

One one hand, it was disconcerting and yet I always knew when she got off.....

Probably tears of joy. You give it to her real good

Did you try asking her about it?

Why havent you asked her? I'm curious about this one

Maybe her love for you is a lot lot lot.

She doesn't say anything? Just cries?

Maybe she’s like me except for different reasons. I cry all the time

Only she can tell you. We’d only be guessing and probably wrong.