As for what Jenaphor said, I think it's spot on. Instead of saying something like, "I feel really neglected. I feel like we don't spend enough time together. You're always busy." To me, that feels like an ultimatum. Like you're making me choose between you and my work, hobbies, or his kids, etc. You're basically saying, "Spend more time with me now or I'm going to be sad all the time."
Instead, it's good if you leave it more open ended. Something like, "I really enjoy it when we watch a movie together or go get dinner. It's one of my favorite things to do. Hint, hint - call me this weekend if nothing is going on!!! *wink*" And then, here's the important part: Just leave it at that. Don't bring it up again. You made your request known, you told him you'd like more time together. If he cares about you and if he truly enjoys your company, then he's going to accomodate your request out of love and respect for you. But, it's not forced and it's not whiny and demanding. And don't expect him to respond with, "OK, come on over tomorrow night!" Just let the request sit with him for a while - let him think about it - and he will slowly begin to find ways to include you in more things.
Basically, don't do this: "Wah, wah, wah, I never get my way. You always do this and you always do that. And you never this and you never that. And I feel bad and I feel down and I feel left out and I feel rejected." That kind of talk closes me off. I shut it down real quick. I'm not very responsive to it. It sounds complainy.
Instead, be upbeat and suggest things here and there and tell him that those things make you happy. Or flirt. Hug him and say, "What do you say we go to dinner" and then purr like a kitten. Or, wrap your leg around him or whatever. (I'm just thinking of stupid examples here). Be playful and funny about it - it keeps things light and it appeals to Ne. You're essentially requesting the same exact thing, but you're not acting like a Debbie Downer and you're leaving it up to him to accomodate you. And, if he cares for you - he'll do it sometimes. Maybe not always - but he will think it through and try to make you happy.
Just keep in mind that you may want to spend 3 nights a week with him, and he may only want 1 night/week for now. You can't expect him to come all the way up to your level. If you want 3 nights and he wants 1, then your goal should be to get him to 2 (in the middle) - but not 3. Always look for the middle ground between what he wants and what you want.