How do I ask my coworker for his number?

Okay so me and one of my coworkers, who recently started working at the company I'm working at, have been spending a lot of time working together lately. We flirt a lot, we have great talks, he asks me to join him on breaks and he just seems quite interested in me overall. I have a huge crush on him, and due to my vacation I sadly won't be able to see him for a few weeks. The only "issue" here is, that he's 8 years older than me and I'm scared it would be weird if I would ask him for his number, or I'm misreading the signs. I would be very grateful if maybe some of you would have any ideas on how i could pull this off without making a fool of myself.
Updates
+1 y
Thank you for the (mostly) helpful advice! I just wanted to let you know, that after I subtly let him know, that I missed him during my time off, he asked me if I'd like to stay in touch (like apart from work) and I gave him my number. I planned on asking for his number that very moment, but he got ahead of me :D We arranged a date almost immediately, we're going on the third one this week, and are really hitting it off! So thanks again for the advice :)
How do I ask my coworker for his number?
Post Opinion