The singers have been dating for seven months, and the 'Ridin' Solo' hitmaker - who is recovering from a fractured vertebra - loves having the support of the former 'American Idol' contestant.
He said: ''We became friends but it wasn't until we were performing together in the Bahamas that things began to hot up. We got to talk more and more. We've been together happily for seven months now.
''Being in a relationship has changed me a lot. When I feel lonely I can pick up the phone and she's there for me. It's really cool to have that backbone.
''Jordin has the most amazing memory ever. If a song plays on the radio she can sing it back to you - her memory is ridiculous. I wish I had some of that. She also is a great cook.''
While Jordin has been nursing Jason back to health following his injury - which was sustained during tour rehearsals - he has been providing support to his girlfriend after she was left devastated by the death of her friend and idol Whitney Houston in February.
He told the Daily Star newspaper: ''That was a shock for everyone but for Jordin it was really tough, they got quite close on the movie set.
''She was Jordin's idol - that coinciding with being her friend - so it was really tough for her.
''I helped her as much as I could. Whitney will go on. She was the greatest singer of all time.''