> recently when i have sex with my partner i cant seem to ejaculate.

The operative term is "recently". The question I have for you is what has changed about you, her, and/or the relationship?

If you are masturbating no more than before when things were workling well, then this is not an issue. It may become one if you go overboard and do it a lot more on one or two days, that includes the day you have relaltions. So, if you have done this and have either approached you maximum or actually reached the maximum number of times a day your body will respond then you might find it difficult or impossible to achive a climax. The cure for this is obvious--don't do it as much on those days, if at all.

How have you been reaching your climaxes before? Hand job? Oral (and/or a hand job)? Intercourse? Has anything changed? If so, what?

> my partner thinks i'm not interested in her and it is becoming a problem in our relationship.

This is a common belief with girls who are new to the art of eros. Please take her aside and talk to her about his and reassure her that such is not the case. While doing this, inform her about the four reasons guys have orgasms.
1. Stress reduction
2. Pure pleasure
3. Expressing the love he has for her
4. Making babies

She must also know that orgasms like erections have a mind of their own and that not being able to achive one is absolutely no reflection on her or on your feelings about her. It is quite common for a guy to be in a happy loving relationship in which the two engage in sex regularly and frequently and yet the man will still masturbate in between times. Why? The answer is #1.

Please report back and tell us what if anything has changed? Next, look at how many (more?) times you have been masturbating and if the number is one or two times higher than normal, consider that you are approaching or have approached your body's daily allotment.

Here are some other factors to look into:
a. If you are unable to climax from a hand job, then teach her how to stimulate your penis as I have described numerous times so that she can then mimic your movemnts, rhythms, and pressures.

b. If you cannot achieve an orgasm soley from oral stimulation, then combine it with a hand job, as above.

c. If you are experiencing problems during intercourse, then you may also have the incorrect perception of what stroking and thrusting are all about. They are not to build a man's arousal--this is the why of making out and what all the kissing and caressing are all about. Intercourse should serve to maintain the existing high level of sexual tension and ardor and then to peak it via thrusting. So, if you are placing the cart before the horse, then you need to change the focus and order of things. Spend no less than half an hour making out and more (within reason) if possible.