heart rate ≈ sexual excitement

1. Measure heart rate during sex with both you and partner's smartwatches

2. Scan 2 QR codes on each smartwatch with one smartphone
- If the smartwatch is connected to the smartphone, https://github.com/zendoclab/love is automatically displayed on the smartphone
- If not connected, open the above web address

3. Check the combined heart rate graph of you and your partner on smartphone

4. Interpret the combined heart rate graph of you and partner
- It's good when both heart rates rise similarly
- It's bad when one heart rate rises too quickly or doesn't rise at all