The male model has been dating Saturdays beauty Mollie King since April but admitted they rarely see each other because he is so focused on his career.
He said: "I`m a useless boyfriend. Even if I am there, I`ll go out in the evening or go to the gym as I`m very restless.
"Our careers are very important to us so we mainly keep in touch on BBM and our phones."
However, David, 31, believes Mollie is the one for him and says he wants to spend the rest of his life with her.
Speaking about his plans for when his modelling career ends, he told the Daily Star newspaper: "I`d love to invest in a hotel in somewhere like Mumbai and move over. Whatever will be will be.
"We don`t need to worry about the future when we`ll be spending the next 40 years together. I can definitely see us lasting that long."
Mollie has previously revealed their relationship works so well because David is like a best friend that she also "fancies".
She explained: "On our first date we went out for dinner but kept it low-key. I actually wanted to be single for a while, having just come out of a two-year relationship and being heartbroken.
"I get on with David like a best friend, but it helps that I fancy him too! When he met my friends and family, to them it was just me bringing home my new boyfriend. I told him, if you get in with Mum, you`ll be fine. Luckily, she really liked him!"