When ISFPs have a crush on someone, they may exhibit a combination of subtle and overt behaviors. Here is a detailed description of how ISFPs may act around their crush:

1. Reserved and Observant: ISFPs are typically introverted and tend to be reserved around their crush. They may observe their crush from a distance, taking in their mannerisms, interests, and behaviors. ISFPs are highly perceptive and may notice even the smallest details about their crush.

2. Shy and Nervous: ISFPs may feel shy and nervous around their crush, especially in the beginning stages. They may struggle with initiating conversations or making the first move. Their fear of rejection or being misunderstood can make them hesitant to express their feelings openly.

3. Thoughtful and Considerate: ISFPs are known for their thoughtfulness and consideration towards others. When they have a crush, they may go out of their way to do small acts of kindness or show gestures of care. They may remember their crush's preferences, surprise them with small gifts, or offer help when needed.

4. Expressive through Art or Creativity: ISFPs are often highly creative individuals who use art as a means of self-expression. When they have a crush, they may channel their emotions into their artistic pursuits. They might create artwork, write poetry, or compose music inspired by their feelings for their crush.

5. Attentive Listeners: ISFPs are excellent listeners and value deep, meaningful conversations. When they have a crush, they will pay close attention to what their crush says, showing genuine interest in their thoughts and opinions. They may ask thoughtful questions and engage in conversations that allow them to connect on a deeper level.

6. Non-verbal Cues: ISFPs may use non-verbal cues to express their interest in their crush. They may maintain eye contact, smile frequently, and display open body language when around them. ISFPs may also blush or become slightly more animated when their crush is present.

7. Supportive and Encouraging: ISFPs are naturally supportive individuals who want to see others succeed. When they have a crush, they will often be their biggest cheerleader. They will offer encouragement, provide a listening ear, and be there to support their crush's goals and aspirations.

8. Respect Boundaries: ISFPs are respectful of personal boundaries and will not push their crush into uncomfortable situations. They may take things slowly, allowing the relationship to develop naturally. ISFPs understand the importance of giving their crush space and time to reciprocate their feelings.

9. Sensitive to Rejection: ISFPs can be sensitive to rejection, and the fear of being rejected may make them hesitant to make their feelings known. They may fear that expressing their emotions could jeopardize the existing friendship or lead to embarrassment. This sensitivity can sometimes make it challenging for ISFPs to take the initiative in pursuing their crush.

10. Romantic Gestures: Once ISFPs feel more comfortable and confident in their crush's reciprocation, they may start to show more overt romantic gestures. This can include planning special dates, surprising their crush with thoughtful gestures, or expressing their feelings through heartfelt words or letters.

It's important to note that every individual, including ISFPs, may have their unique way of expressing their feelings. While this description provides a general understanding of how ISFPs may act around their crush, it's essential to remember that each person is different and may exhibit variations in their behavior.