No romo tho- is an expression to tell the person you are talking with, that you don't mean whatever you said in a romantic way. You may have said something like a pickup line, or something in general in a flirtatious way but wanted to clarify what your intentions were.
"I turn the lights off whenever I leave the house but... you're one of my turn ons" joked Ettoe. "No romo tho-".
"It's all good" laughed Toe while grinning from ear to ear, ecstatic at the compliment.