Is It Serious or Is It Casual?

"Hopeless Romantic" on the forum has a question about the I Love You sign - in what context is it casual or serious? Here is "Hopeless Romantic's" question:

I am hearing and I started seeing a deaf man recently. I am learning ASL and we have really been connecting. So, we were parting ways and he was getting into his car, and he threw up the "I love you" sign. I know some signs can be interpreted differently, depending on context. I was wondering if this is one of those times. Could he be saying "love ya" or is it really a more serious thing? As with any dating situation I don't want to ask him and make an issue out of nothing. Help?

Can you explain to "Hopeless Romantic" about the I Love You sign so she doesn't get unnecessary stars in her eyes?

Related: I Love You Handshape