Hi there and thanks for your question. Without examining him, it's not possible to know exactly what these pimples on your boyfriend's penis are.

While normal pimples can sometimes turn up on the penis especially in adolescents, there are quite a few other things which can cause pimple-like bumps. Some of the more common things are hair follicles, pearly penile papules, molluscum contagiosum, sebaceous (epidermoid) cysts and genital warts. I'll give you more information about each of these things below.

Hair follicles are little bumps around the base of hairs. They are completely normal and should be left alone. They can occasionally become inflamed, but any inflammation should go away by itself. If it doesn't, it should be seen by a doctor. They shouldn't be squeezed because this can cause infection.

Pearly penile papules are small skin-coloured domes (bumps) which usually occur around the base of the head of the penis. They are also quite normal. They are not dangerous and not sexually transmissible or infectious. They should not be squeezed because squeezing can cause infection and damage the skin.
There is a photo of them on the following webpage: Medscape Reference - Pearly penile papules (click on "View Image Library")

Molluscum contagiousum are small pimple-like lumps caused by a type of virus. It is a fairly common skin condition and is infectious. It can occur anywhere on the body, including the genitals and pubic area. The lumps usually go away by themselves after a few months but they can also be treated by a doctor. These should not be squeezed because it doesn't help them go away and could make them more infectious. There is a photo of molluscum contagiosum on the penis on the following webpage: American Osteopathic College of Dermatology - Molluscum contagiousum

Sebaceous (epidermoid) cysts are bumps that can look like pimples. They can be small or fairly large (as you described the pimples that your boyfriend has). They form when the normal little cysts in the skin become blocked. They are relatively common, and more common in younger people. They are not infectious. They tend to start as a firm lump, sometimes with a dip in the centre, and then over time they can get red and sore. They can be left alone or can be removed by a doctor. They do sometimes recur after being removed and some scarring can occur. Squeezing them is not a good idea because it can cause infection and scarring.

Genital warts are warts that occur on the genitals. If your boyfriend can squeeze something out of the bumps then this is unlikely to be what they are but they are still worth mentioning. Genital warts can look like warts anywhere else on the body—they are skin-coloured or pale bumps, can be raised or flat, single or multiple, or they can occur in patches or clusters that are often paler than the surrounding skin and look a bit like cauliflower. Genital warts are sexually transmissible and need to be diagnosed and treated by a sexual health nurse or a doctor. For further information and photos see Genita Warts.ca

The most important thing is for your boyfriend to go and see a doctor and have these pimples diagnosed. As you can see, there are quite a lot of different causes for pimple-like lumps on the penis and he really needs to have them correctly diagnosed and treated if need be. He needs to stop squeezing them in the meantime so that he does not risk infection and more scarring.

The best place to go would be to a GP that he feels comfortable with or to Family Planning WA who provide sexual health services for men and women.

All the best and take care.