It sounds like he should run this by his physician. However, your support is prime in this situation. I feel it can be resolved to the satisfaction of all parties with patience and just enjoying being close with your partner without any "must-have" conclusions at this time. In the meantime, there are many facets of sex to explore such as oral that may fill the bill until this ejaculation problem can be rectified. But a qualified physician would put these fears to rest.
The boy needs to relax and enjoy the moment.