The phrase “lingam massage” has entered the public eye as a type of genital massage with Hindu influences, it doesn’t literally translate to the male reproductive organ. Lingam is actually a representation of the Hindu god Shiva, which happens to be phallic in shape. You can understand why it has come to mean penis to so many people.
However, some Hindu practitioners still strongly associate the concept with Shiva. To them, using the word as part of the phrase “lingam massage” might seem offensive because it reduces the meaning.