<human>: Can you summarize the given text in a few sentences?

Tonight I got a facebook message from my ex, asking me how I was and telling me a little bit about himself. He also asked about my boyfriend, who I was just friends with at the time of our break up. He's clearly drunk and celebrating something. Then he ruins it by writing "by the way I kinda miss you. A lot." 

By the way, we broke up over THREE YEARS ago. Also I haven't spoken to him much over that period, except for maybe one or two Facebook exchanges. 

Anyway, this is making me feel awful because a) I don't know to respond to the awkward part, and b) I am feeling residual guilt about our break up. Help? Male opinions are especially appreciated.

Thanks.
<bot>: Ex who I broke up with 3 years ago drunkenly sent me a nice message, but then ruined it with a "I miss you." How on earth do I respond?