Arm wrestling with non mahrams

Q: About 7–8 years ago, when I was newly married (around 1 year of marriage), my husband suggested we do arm-wrestling for fun. With his permission, I also did arm-wrestling with his four brothers. At that time, I did not feel any lust or desire from my side at all. 

I noticed that the brothers looked a bit excited, which could have been because they had never held a woman’s hand before but now I am worried. What if they might have felt lust at that time, 1 of them asked for a re match even though I lost from all of them but I said no 1 time is enough now I cannot ask them directly as it would be very embarrassing and it was almost a decade ago. Now I do proper hijab and cover my face too. 

My question is: Does this cause hurmat-e-musaharat, and is my nikah still valid? 

I also suffer from waswas (intrusive doubts) in religious matters, so I want clarity and peace of mind.

Payflex

Q: Is it permissible for a merchant to offer the Payflex payment option to their clients? Similarly, is it permissible for one to use the Payflex payment option when purchasing from a store which offers the Payflex payment option? 

Below are the details regarding how the Payflex payment option operates: 

A customer wishes to purchase an item costing R2000 from an online store. Instead of paying for the item in full immediately, he has the choice of using Payflex when concluding his purchase. 

Payflex allows the customer to split the cost of the purchase into 4 equal, interest-free and fee-free payments. When checking out, the customer completes a quick form and is instantly vetted. Upon Payflex approving the customer’s credit rating, Payflex will immediately pay the merchant in full for the sale at the time when the customer buys the item from the merchant. 

The customer will pay Payflex the first 25% of their purchase (R500) at the time of the purchase. Payflex will then collect the other 75% of the amount in three instalments of R500 each over the next six weeks. 

Payflex charges the merchant a fixed fee for processing the transaction between the customer and the merchant. Is this transaction permissible in Shariah?