Calmly explain your needs and expectations.
It may sound simple or even trivial, but stick with me here for a moment.
To show you why it works, I'm going to use an illustration from my own life.
Years ago, before I met my husband, I dated a very nice guy. He had a lot of qualities I was looking for, but one habit was a major problem for me.
He was a smoker.
Now this may seem like an inconsequential habit, but my father died from smoking and since then it has been a dating deal breaker for me.
have said, "Listen, I like you, but you have a choice: the cigarettes or me," but I knew that throwing down an ultimatum like this would have immediately put him on the defensive.
From what I hear, it's hard enough to kick the smoking habit when you're committed to doing it for yourself. So I can't imagine it would have worked out if he went cold turkey while wrestling with feelings of resentment that I had forced him to do so against his will.
Instead, I explained my own personal needs, just as they related to ME.
I said, "I think you're great and I really enjoy spending time with you. I do need to let you know that since my dad passed, I made a promise to myself that I won't get seriously involved with a smoker. It's just too hard for me. So please understand that I am not asking you to change for me. I'm just letting you know that this a decision I have made for myself and whatever you decide to do with that information is up to you."
Do you see the difference in the approach? It allows you to stand up for your beliefs and let the other person know what expectations you have... BUT it allows the other person the dignity of making their own choice based on the information you give them.
Hopefully, he'll be smart enough to realize how amazing you are and will gladly do anything it takes to rise up to meet your needs and expectations.
But even if he isn't able to, then you have peace of mind knowing that you never lowered yourself to the level of threatening or groveling. You simply made him aware of what you needed, and if he can't meet those needs then it's his problem and HIS loss!
So how would this work for the commitment situation?
Well (provided that you've got a fairly solid foundation from dating for some time) you could say something like this:
"I really love what we have and I enjoy every moment we spend together. I'm not sure what your thoughts or plans are for the future, but personally, I'm no longer interested in open-ended dating just for fun. At this point in my life, I am looking for someone I can share my life with - get married, have kids one day, etc.
I'd like to start a dialogue about this so I know where you stand. That way, I'll be clear on whether we're on the same page or I should consider dating other people who are open to the idea of settling down."
I guarantee that will be more productive than saying "There had better be a ring on my finger by Christmas or I'm OUTTA HERE!" But by keeping the focus on yourself and your own needs, you give him the power to choose his next move.