Kevin Jonas and his wife Danielle Deleasa are expecting their first child.

The Jonas Brothers star, 25, is thrilled his wife of three and a half years is pregnant but admits he is nervous about becoming a father.

He told E! News: ''I was overjoyed. It's been the most exciting thing in my life so far. I'm excited and I'm nervous.''

The couple, who wed in December 2009, have frequently discussed their desire to start a family together on their E! reality show, 'Married to Jonas'.

Danielle, 26, previously said she was under pressure from her family to have a baby, saying: ''Having kids is a big question right now; it does come up a lot.''

Kevin added: ''We're at that [3-year] mark and people are like, 'All right guys, what's your plan? When are you going to have those grandkids?' I'm starting to feel that pressure a little bit.''

Kevin previously revealed that their reality show is like therapy.

He explained: ''The other night we had an argument. Sometimes you say things you don't necessarily mean or can be misconstrued.

''It was a selfish moment for sure, but at the end of the day you look back and think, 'Wow'. Don't you wish you had that option in a relationship to be able to watch back your arguments so you can see who was right and who was wrong?''