It's important to approach this topic with sensitivity and respect for your mother's privacy and dignity. Sexual arousal and intimacy can be a part of life at any age, including into the 80s and beyond. However, the signs of sexual arousal can be subtle and vary widely from person to person.

Some general signs of sexual arousal may include:

• Physical responses: Increased blood flow to genital areas, changes in breathing or skin flushes, and increased heart rate. These signs may not be easily visible or noticeable, especially without intimate contact.
• Behavioral cues: Increased affection, such as touching or massages, lingering eye contact, flirtatious remarks, or other forms of closeness that are different from usual interactions.

Given that your mother sometimes gives you a massage, it's possible she could be expressing affection or comfort rather than sexual intent. A massage can be a way to relieve tension and show care without any sexual connotations.

It's also valuable to remember that boundaries are very important. If you're ever uncertain or uncomfortable about any physical contact, it's okay to set clear and respectful boundaries and communicate your feelings openly and kindly.

If you're concerned about her well-being or behavior changes, consider discussing your feelings with a trusted healthcare professional or counselor who can offer guidance suited to your unique situation.

Respect and care are the most important factors in all interactions, especially with elderly parents.