What are some test to run on your partner to see if he is serious?
474467
The best test is to ask serious questions. Ask questions that matter to you so you can see where he stands. "Do you think we'll get married", "Do you want kids", "When do you think the right time is to be married", etc etc.
315357
Ask him. Point blank, out of the blue, look him straight in the eye and say: "Are you cheating on me?" His reaction will tell you exactly what is going on.
770440
ask him to evaluate him self better. just say..."lyk watt do u mean"...or something.
255743
Tell him that you are thinking marriage... gauge his reaction, that will be a good indicator of how he thinks about the relationship.
1122641
The only way to know for sure is for him to get a semen analysis done. As far as his last girlfriend, there are many factors that determine whether pregnancy occurs or not, and typically a year or more of trying warrants a trip for both parties to get examined, and typically see a fertility specialist.  He really needs to see his doctor to get tested.
927273
Confront your partner and express your feelings.
233896
Go ask him. How should i know.
1144339
Ask him straight up but, have fun with it, make it so that it's not too serious. What ever you do, do not pressure him. You can also try paying close attention to him, he might give out little signs and hints.
36536
Depends on if you trust him or not. If he's trustworthy then you should believe him...if you have that gut feeling that he just isn't telling you how he seriously feels..then you should try to find someone who WOULD give anything for you. Good Luck!
1115110
Say "are you cheating"?
358355
try to talk to him to see what's wrong.
170325
What is your rush?\nHave a serious talk with him.  Ask him what his intensions are.  Ask him if he knows why he hasn't asked already.\nIf he is serious, he should at least talk with you.\nIf he stringing you along, better to find out now than later.\nSame if he has serious doubts.
923075
Ask him upfront and openly. If he gets mad and leaves you for asking that question, he was cheating, so you saved yourself.
892708
Probably a t-test. \n\nTell us what hypothesis you are testing.
195113
Those indicates that he loves you. My advise would be, to get more intimate with him, just the way he wants you to, and see how he reacts. Even after doing as he wants you to if he questions your work, then he is just saying things, and not being original. I think that's the only way you can surely test if he is being honest with you or not.
28357
First I would validate that s/he indeed is cheating.\n\nS/he might have other issues that you are not aware of.\n\nConfront the person if possible, in a non-hostile manner.
517612
You cant tell. Well, try to talk about your relationship and see if he gets all soft on how he loves you and such.