grandpa friend

Similar to a mom friend or dad friend, a grandpa friend is usually the grumpy one of the group, and has a hard time showing his love for other friends in the group but its there. He generally complains about topics such as back pain (or chronic pain anywhere), how he doesn't like the current generation (even though he likely is part of it), or how things were better when he was younger despite being no older than his early 20s.