When we talk about happy endings, we don't mean the kind you read about in fairytales. We mean the ending where you walk away with a big grin on your face because you've achieved orgasm with a little bit of help from your partner. Many people choose to do this after a massage, as you will be so relaxed that your orgasm will feel fantastic once you get their with a guiding hand.
There are many different ways that happy endings can happen, and that choice is up to your partner. They may surprise you with what they want to do to please you and make you happy, but you may wish to discuss it first.
Happy endings come in many forms. For some, a happy ending means a hand-job, where your partner will rub your member until you cum. For others, a happy ending could be in the form of covered or uncovered oral, possibly ending with cum in mouth or cum in mouth with condom. If you have more diverse tastes, your partner may take this into account. A particularly busty partner may perform Russian on you to help you achieve release, while a stockinged one may slowly rub their legs and feet up and down your shaft to help you orgasm. Each person has their own preference for a happy ending, but some may be willing to discuss it with you if there is one that you'd love more than any other.
Ultimately, however, the choice and final decision belongs to your partner. If they feel the best way to get you to cum is through a slowly, sensual hand-job, then just lie back, relax, and enjoy it. While it may not be the ending you envisaged, trying to force the issue may be more damaging. Let your partner please you in the way they want to, as an enthusiastic hand job is better than a disinterested blow job.